EP0675667A2 - Lautsprecher und Verfahren zu seiner Herstellung - Google Patents

Lautsprecher und Verfahren zu seiner Herstellung Download PDF

Info

Publication number
EP0675667A2
EP0675667A2 EP95104716A EP95104716A EP0675667A2 EP 0675667 A2 EP0675667 A2 EP 0675667A2 EP 95104716 A EP95104716 A EP 95104716A EP 95104716 A EP95104716 A EP 95104716A EP 0675667 A2 EP0675667 A2 EP 0675667A2
Authority
EP
European Patent Office
Prior art keywords
fibers
diaphragm
water
loudspeaker
polyester
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP95104716A
Other languages
English (en)
French (fr)
Other versions
EP0675667A3 (de
Inventor
Masatoshi Okazaki
Shinya Mizone
Toshihiro Shimizu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Corp
Original Assignee
Matsushita Electric Industrial Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP6266994A external-priority patent/JPH07274283A/ja
Priority claimed from JP07582994A external-priority patent/JP3561946B2/ja
Application filed by Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Publication of EP0675667A2 publication Critical patent/EP0675667A2/de
Publication of EP0675667A3 publication Critical patent/EP0675667A3/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/12—Non-planar diaphragms or cones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2231/00—Details of apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor covered by H04R31/00, not provided for in its subgroups
    • H04R2231/001—Moulding aspects of diaphragm or surround
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
    • H04R2307/021—Diaphragms comprising cellulose-like materials, e.g. wood, paper, linen
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
    • H04R2307/025—Diaphragms comprising polymeric materials
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2307/00—Details of diaphragms or cones for electromechanical transducers, their suspension or their manufacture covered by H04R7/00 or H04R31/003, not provided for in any of its subgroups
    • H04R2307/029—Diaphragms comprising fibres

Definitions

  • the present invention relates to a loud speaker to be used for various acoustic apparatuses, and a method for producing the same.
  • Figure 1 is a half cross-sectional view showing a configuration for a typical loud speaker 20.
  • Figure 2 is an exploded perspective view showing details of the loud speaker 20. The same constituent elements are indicated by the same reference numerals in Figures 1 and 2.
  • the loud speaker 20 includes a lower plate 3 integral with a center pole 2, a magnet ring 4 provided on a bottom portion of the lower plate 3 so as to surround the center pole 2, and an upper plate 5 provided on an upper face of the magnet ring 4.
  • the lower plate 3, the magnet ring 4, and the upper plate 5 are coupled to one another to constitute a magnet circuit 1.
  • an inner periphery of the frame 6 is coupled on an upper face of the upper plate 5.
  • a gasket 7 and an outer periphery of a diaphragm 8 are attached to an outer periphery of the frame 6 using an adhesive.
  • a voice coil 9 is coupled to an inner periphery of the diaphragm 8.
  • a middle portion of the voice coil 9 is supported by an inner periphery of the damper 10, an outer periphery of the damper 10 being supported by the frame 6.
  • a lower portion of the voice coil 9 is inserted into a magnetic gap 11 formed between the center pole 2 of the lower frame 3 and the upper frame 5 (which are included in the magnetic circuit 1) without being eccentric.
  • a dust cap 12 for preventing dust from entering the magnetic circuit 1 is provided on the upper side of a central portion of the diaphragm 8.
  • the material constituting the diaphragm 8 has such properties as high elasticity, low density, and high internal loss for the following reasons.
  • the high-frequency range resonance frequency of the diaphragm 8 increases as a specific elasticity E/p (where E represents the elasticity modulus and p represents the density) of the material constituting the diaphragm 8 increases, that is, as the elasticity modulus E increases and as the density p decreases.
  • E represents the elasticity modulus
  • p represents the density
  • the diaphragm 8 achieves a flatter frequency characteristic curve and a lower distortion rate as the internal loss of its material increases.
  • a principal material used for the diaphragm 8 of the conventional loud speaker 20 is paper which is composed mainly of natural pulp such as wood pulp. This is because paper has an appropriate elasticity modulus and internal loss as well as low density, and therefore provides advantages that a diaphragm composed of a synthetic resin or a complex thereof cannot attain.
  • the voice coil 9 is required to withstand a large input signal applied thereto.
  • the voice coil 9 is required to have an increased inflammability and heat resistance for the following reasons.
  • FIG 3 shows an exemplary configuration for a conventional voice coil 9 designed so as to overcome the above-mentioned problem.
  • the voice coil 9 includes a bobbin 13 composed of a strip of a metal foil, e.g., aluminum, bent into a cylindrical shape. Kraft paper 14 is wound, for reinforcement and insulation, around an outer periphery of the voice coil 9 where a coil 15 is not wound.
  • the bobbin 13 is obtained by winding the voice coil 9 on a portion of the bobbin 13 where the kraft paper 14 is not wound.
  • the coil 15 is directly wound on the metal foil constituting the bobbin 13, so that the metal foil functions to radiate the heat generated in the coil 15, thereby preventing elevation of temperature.
  • diaphragms for loud speakers made of materials consisting of inorganic fibers and/or organic synthetic fibers mixed with paper so as to improve the elasticity of the paper.
  • the expected effect of improving the elasticity has not been attained.
  • paper diaphragms tend to absorb, and therefore are generally susceptible to, moisture.
  • paper diaphragms are not appropriate for such applications as loud speakers to be attached on the doors of automobiles, which require a particularly good water-proofness.
  • diaphragms for loud speakers requiring a high degree of water-proofness have typically been produced by adhering water repellent on pulp fibers during fabrication, or impregnating the fabricated paper diaphragm with a synthetic resin solution so as to provide the paper with water-proof properties.
  • the loud speakers to be attached on the doors of automobiles have particularly been required to be sufficiently resistant against surfactants included in detergents for washing automobiles, e.g., car shampoos.
  • the above-mentioned method of adhering water repellent on pulp fibers or impregnating the fabricated paper diaphragm with a synthetic resin solution cannot attain sufficient resistance against such surfactants.
  • Japanese Patent Publication No. 57-40718 describes a diaphragm produced by using a material including a principal material of short fibers, such as polyethylene, polypropylene, nylon, and polyacrylonitrile, or synthetic pulp obtained by fibrillating these fibers, and a subordinate material of fibers such as inorganic fibers, organic synthetic fibers, or natural fibers mixed in the principal material, subjecting the material to a paper-fabrication process, and melting the resultant complex synthetic pulp so as to mold it into a desired shape.
  • This diaphragm has excellent environmental characteristics such as water-proofness.
  • the diaphragm also has the three following problems.
  • the synthetic pulp used for the above-mentioned diaphragm has relatively short fiber lengths and therefore has low freeness. As a result, the fabrication process takes a long time.
  • the synthetic pulp used for the above-mentioned diaphragm has a relatively high beating degree, and has relatively short fiber lengths, so that it is difficult to obtain a bulky product after a percolation process. Moreover, since the synthetic pulp is melted during the drying-molding process, the obtained molded product has a film-like shape, so that it is difficult to increase the thickness of the molded product and to adequately reduce the density and increase the internal loss thereof.
  • the metal foil used for the bobbin 13 which is incorporated with a view to improving the heat resistance of the voice coil 9, has a large weight, thereby deteriorating the performance of the loud speaker. Moreover, since metals are good electrical conductors, the use of a metal foil for the bobbin 13 may cause a short-circuiting of the coil 15.
  • a sheet composed of heat-resistant chemical fibers such as paper composed of aromatic polyamide fibers, e.g., aramid paper or NOMEX paper (manufactured by Du Pont Ltd.) is occasionally used for the bobbin 13 of the voice coil 9.
  • paper slightly absorbs moisture.
  • the moisture absorbed in the paper is gasified so that swelling may occur in a portion of the bobbin 13 where the coil 15 is wound.
  • a portion of one or more of the aromatic polyamide fibers may be left at the severed surface.
  • These fibers may also remain in a plumous state on the surface of the sheet. In either case, such portions of the aromatic polyamide fibers can cause extraordinary noises during the operation of the loud speaker, thus deteriorating the quality of the loud speaker.
  • loud speakers to be attached on the doors of automobiles are required to be particularly water-proof, so that the voice coil 9 is also required to have an improved water-proofness as well as the diaphragm 8.
  • a loudspeaker of the invention includes: a magnetic circuit portion including a magnetic gap; a frame coupled to an upper face of the magnetic circuit portion; a diaphragm, an outer periphery thereof being attached to an outer periphery of the frame; and a voice coil coupled to an inner periphery of the diaphragm, the voice coil being inserted into the magnetic gap, wherein the diaphragm is formed by mixing water-proofed natural pulp or organic synthetic fibers as a principal material with polyester-type fibers having a low melting point as a subordinate material, only intersections among the fibers being melt-bonded.
  • a method for producing a loudspeaker of the invention includes: a beating step for obtaining a principal material of natural pulp or organic synthetic fibers; a mixing step for mixing the principal material with polyester-type fibers having a low melting point, and further with a water repellent to be affixed thereto; a paper fabrication step for subjecting a slurry obtained in the mixing step to a paper fabrication process; a forming step for drying the fabricated slurry by being heated with hot air at a predetermined temperature higher than the melting point of the polyester-type fibers, and forming the fabricated slurry into a predetermined shape; a trimming step for conducting a trimming process so as to obtain the diaphragm; and a fabricating step for forming a loudspeaker using the obtained diaphragm.
  • the melting point of the polyester-type fibers is in the range from about 120 to about 180°C.
  • a thickness of the polyester-type fibers is in the range of about 0.5 to about 5 deniers.
  • a fiber length of the polyester-type fibers is in the range of about 1 to about 15 mm.
  • the polyester-type fibers are mixed in an amount of about 1 to about 50% by weight based on the principal material.
  • a loudspeaker includes: a magnetic circuit portion including a magnetic gap; a frame coupled to an upper face of the magnetic circuit portion; a diaphragm, an outer periphery thereof being attached to an outer periphery of the frame; and a voice coil coupled to an inner periphery of the diaphragm, the voice coil being inserted into the magnetic gap, wherein the diaphragm is formed of a molded product obtained by dry-molding a slurry of a principal material of water-repellentized natural pulp mixed with water-proof synthetic pulp having a minute film-like shape, a water-repellent synthetic resin film being disposed on a surface of the molded product.
  • a method for producing a loudspeaker of the invention includes: a beating step for obtaining a principal material of natural pulp or organic synthetic fibers; a mixing step for mixing the principal material with water-proof synthetic pulp having a minute film-like shape, and further with a water repellent to be affixed thereto; a paper fabrication step for subjecting a slurry obtained in the mixing step to a paper fabrication process; a forming step for drying the fabricated slurry by being heated, thereby obtaining a molded product having a predetermined shape; an immersion step for impregnating the molded product with an organic resin solution mixed with a water repellent, and drying, thereby forming a water-repellent synthetic resin film on a surface of the molded product; a trimming step for conducting a trimming process so as to obtain the diaphragm; and a fabricating step for forming a loudspeaker using the obtained diaphragm.
  • the synthetic pulp is formed of a meta-type aramid resin.
  • the diaphragm is further mixed with water-proof fibers.
  • the water-proof fibers are mixed into the principal material in the mixing step.
  • the water-proof fibers are polyester-type fibers.
  • a loudspeaker includes: a magnetic circuit portion including a magnetic gap; a frame coupled to an upper face of the magnetic circuit portion; a diaphragm, an outer periphery thereof being attached to an outer periphery of the frame; and a voice coil coupled to an inner periphery of the diaphragm, the voice coil being inserted into the magnetic gap, wherein the voice coil further includes: a cylindrical bobbin formed of a sheet obtained by mixing water-proof heat-resistant synthetic pulp having a minute film-like shape with inorganic fillers and water-proof heat-resistant synthetic fibers and then subjecting to a paper fabrication process and to a pressure-heating process using a calender; and a coil wound on an outer surface of at least a portion of the bobbin.
  • a method for producing a loudspeaker of the invention includes the steps of: mixing water-proof heat-resistant synthetic pulp having a minute film-like shape with inorganic filler and water-proof heat-resistant synthetic fibers; subjecting the mixed synthetic pulp to a paper fabrication process; forming a sheet by subjecting the fabricated synthetic pulp to a pressure heating process using a calender; forming a cylindrical bobbin using the sheet; forming a voice coil using the bobbin; and fabricating a loudspeaker using the obtained voice coil.
  • the synthetic pulp is formed of a meta-type aromatic polyamide.
  • the synthetic fibers are short fibers formed of a para-type aromatic polyamide.
  • a thickness of the sheet after being processed by the calender is in the range from about 30 to about 500 f,.lm.
  • a bulk density of the sheet after being processed by the calender is in the range from about 0.6 to about 1.5 g/cm 3 .
  • the invention described herein makes possible the advantages of (1) providing a loud speaker including a diaphragm having a high elasticity modulus and excellentwater-proofness and/ora tight-weight voice coil having excellent inflammability, water-proofness, and adhesion, the loud speaker therefore being capable of withstanding a large input; and (2) a method for producing the same.
  • Figure 4 is a half cross-sectional view showing a configuration for a loud speaker 120 produced according to a first example of the present invention.
  • the loud speaker 120 includes a lower plate 103 integral with a center pole 102, a magnet ring 104 provided on a bottom portion of the lower plate 103 so as to surround the center pole 102, and an upper plate 105 provided on an upper face of the magnet ring 104.
  • the lower plate 103, the magnet ring 104, and the upper plate 105 are coupled to one another to constitute a magnet circuit 101.
  • an inner periphery of the frame 106 is coupled on an upper face of the upper plate 105.
  • a gasket 107 and an outer periphery of a diaphragm 108 are attached to an outer periphery of the frame 106 by using an adhesive.
  • a voice coil 109 is coupled to an inner periphery of the diaphragm 108.
  • a middle portion of the voice coil 109 is supported by an inner periphery of the damper 110, an outer periphery of the damper 110 being supported by the frame 106.
  • a lower portion of the voice coil 109 is inserted into a magnetic gap 111 formed between the center pole 102 of the lower frame 103 and the upper frame 105 (which are included in the magnetic circuit 101) without being eccentric.
  • a dust cap 112 for preventing dust from entering the magnetic circuit 101 is provided on the upper side of a central portion of the diaphragm 108.
  • Figure 5 is a half cross-sectional view showing the diaphragm 108.
  • a method for producing the diaphragm 108 will be described with reference to a flow chart shown in Figure 6.
  • un-bleached kraft pulp (hereinafter referred to as "UKP") having a freeness (Canadian Freeness: as measured by the Canadian standard freeness measuring apparatus) of 550 cc is beaten so as to give a slurry of UKP.
  • the UKP functions as a principal material.
  • modified polyester fibers (melting point: about 120°C to about 180°C; fiber length: about 1 to about 15 mm; thickness: about 0.5 to about 5 deniers) are added in an amount of about 1% to about 50% by weight based on the absolute dry weight of the UKP.
  • modified polyester fibers having a melting point of 130°C, a fiber length of 5 mm, and a thickness of 2 deniers are added in an amount of 10% by weight based on the absolute dry weight of the UKP.
  • a fluorine-type water repellent is added in an amount of about 0.05% to about 0.5%, e.g., 0.1 %, by weight based on the absolute dry weight of the UKP so as to obtain a mixture to be subjected to a paper-fabrication process.
  • the modified polyesterfibers function as a subordinate material.
  • a product designated as "DICGUARD F-400" manufactured by Dainippon Ink and Chemicals, Inc.
  • DIGUARD F-400 manufactured by Dainippon Ink and Chemicals, Inc.
  • a molding step 630 that is, in a paper-fabrication step, the above-mentioned mixture (slurry) is subjected to a paper-fabrication process by using a screen formed into a desired shape of the diaphragm 108, e.g., a conical shape, and is dehydrated.
  • a forming step 640 the fabricated product is dried by being heated with pressurized hot air at a temperature higher than the melting point of the polyester-type fibers, e.g., 220°C, for about 40 seconds.
  • a temperature higher than the melting point of the polyester-type fibers e.g., 220°C, for about 40 seconds.
  • the pressure of the hot air contributes to the formation of a predetermined shape.
  • the molded diaphragm is subjected to a trimming process in a trimming step 650 so as to have predetermined inner and outer shapes.
  • the diaphragm 108 having a predetermined shape for example, a conical shape with a diameter of 120 mm and a weight of 2.2 g is obtained.
  • the diaphragm 108 obtained in the above-mentioned manner has a freeness of 670 cc, an elasticity modulus of 4 x 10 9 N/cm 2 , an internal loss (tan8) of 0.067, a thickness of 0.73 mm, and a density of 0.052 g/cm 3 .
  • a conventional paper diaphragm was produced by subjecting the above-mentioned UKP having a freeness of 550 cc to a paper-fabrication process and a heat-press molding by using a mold maintained at 180°C with a pressure of 2 kg/cm 2 applied, the diaphragm having the same shape and diameter as the diaphragm 108 of the present example.
  • Measurement of the characteristics of this conventional paper diaphragm revealed an elasticity modulus of 1.4 x 10 9 N/cm 2 , an internal loss (tan8) of 0.035, a thickness of 0.36 mm, and a density of 0.067 g/cm 3 .
  • a diaphragm as a constituent element of a loud speaker, is subjected to long-term use, and is preferably required to have a large strength (stiffness).
  • the molded diaphragm is required to be sufficiently thick.
  • the diaphragm 108 produced according to the present example has a thickness of 0.73 mm, thereby achieving a thick diaphragm 108 with a large stiffness in spite of its small weight.
  • the above-mentioned conventional diaphragm has only a thickness of 0.36 mm, that is, it is difficult to increase the stiffness of the conventional diaphragm by increasing the thickness thereof.
  • the stiffness of such a diaphragm may be increased by increasing the density thereof, there is an adverse effect in that the high-frequency range resonance frequency of a loud speaker incorporating the diaphragm lowers as the density of the diaphragm increases, thereby narrowing the range of frequencies reproducible by the loud speaker.
  • the modified polyester fibers are present as if stitching through the UKP fibers.
  • the UKP fibers and the modified polyester fibers are integrated with each other by being completely fused at the intersections thereof.
  • the intersections of the modified polyesterfibers themselves are also fuse-bonded.
  • the modified polyester fibers constitute a three-dimensional net-like structure present in the interspaces between the UKP fibers.
  • the diaphragm 108 of the present example retains its shape owing to such interfusion between fibers.
  • Figure 7 is a graph showing the sound pressure level (S.P.L.)-frequency characteristics (solid line a) of a loud speaker incorporating the diaphragm 108 of the present example and the S.P.L.-frequency characteristics (broken line b) of a loud speaker incorporating the conventional diaphragm 8 (shown in Figure 1).
  • the S.P.L. was measured with a microphone placed apart from the tested loudspeaker by 1 m.
  • the loud speaker incorporating the diaphragm 108 of the present example is capable of reproducing a broader range of frequencies than the loud speaker incorporating the conventional diaphragm 8.
  • the principal material for the diaphragm is not limited thereto.
  • natural pulp such as wood, cotton, and linen, or organic synthetic fibers having a high elasticity modulus and a high melting point, e.g., an aromatic polyamide and highly crystalline vinylon.
  • the principal material is subjected to a water-proofing process by affixing a water repellent thereto.
  • the low-melting point polyester-type fibers used as the subordinate material preferably have a thickness of about 0.5 to about 5 deniers and a melting point of about 120°C to about 180°C. This is because fibers having characteristics in the above-mentioned ranges do not completely fuse during the drying process and therefore are appropriate for the purpose of obtaining the above-mentioned structure where only the intersections are melt-bonded.
  • the fiber length of the polyester-type fibers is about 1 to about 15 mm, the polyester-type fibers being mixed in an amount of about 1% to about 50% by weight based on the principal material.
  • the freeness of the diaphragm increases as the content ratio of the subordinate material increases.
  • the diaphragm of the present example is produced by mixing low-melting point polyester-type fibers having a relatively large fiber diameter and a long fiber length with natural pulp or organic synthetic fibers having a small density and then subjecting the mixture to a paper-fabrication process.
  • a diaphragm having a high freeness is obtained by a relatively short fabrication process, whereby a bulky product is easily obtained.
  • hot air at a temperature higher than the melting point of the polyester-type fibers is used, so as to fuse only the intersections of the fibers without completely fusing the polyester-type fibers. The pressure of the hot air contributes to the formation of a predetermined shape.
  • the method for producing the diaphragm according to the present invention performs no pressure-drying using a heated mold, which would be performed in the case of producing a diaphragm through a common paper-fabrication process, a diaphragm having a large thickness, a small density, a high internal loss, and a high stiffness can be obtained.
  • a diaphragm having a high elasticity modulus, a high internal loss, and a large thickness can be obtained.
  • a loud speaker having small distortion and a broad reproducible frequency range can be obtained.
  • polyester-type fibers themselves have an extremely low moisture absorption, so that a diaphragm with a sufficient mechanical strength can be obtained even if a water-immersion process is conducted, which is conducted for mixing the polyester-type fibers with natural pulp or organic synthetic fibers and for the paper-fabrication of the mixture.
  • Figure 8 is a half cross-sectional view showing a configuration for a loud speaker 220 according to a second example of the present invention.
  • Figure 9 is a half cross-sectional view showing a configuration for a diaphragm 108A incorporated in the loud speaker 220.
  • the loud speaker 220 differs from the loud speaker 120 with respect to the diaphragm 108A.
  • a method for producing the diaphragm 108A will be described with reference to a flow chart shown in Figure 10.
  • UKP having a freeness (Canadian Freeness) of 550 cc is beaten so as to give a slurry of UKP.
  • the UKP functions as a principal material.
  • a mixing step 620 predetermined additives such as a reinforcement material, a dye, and a binder are mixed with the UKP slurry thus obtained.
  • a reinforcement material such as a reinforcement material, a dye, and a binder
  • meta-type aramid resin pulp is first added in an amount of about 5% to about 20% by weight based on the absolute dry weight of the UKP.
  • a product designated as "CONEX pulp” manufactured by Teijin Ltd.
  • a fluorine-type water repellent is added in an amount of about 2 to about 20 cc to an absolute dry weight of 100 g of the UKP.
  • 10 cc of "DICGUARD F-400" manufactured by Dainippon Ink and Chemicals, Inc.
  • an aluminium sulfate is employed to adjust the pH of the slurry to be in the range of about 4.5 to about 5.0.
  • the fluorine-type water repellent is affixed to the UKP.
  • a molding step 630 that is, in a paper-fabrication step, the above-mentioned mixture (slurry) is subjected to a paper-fabrication process by using a screen formed into a desired shape of the diaphragm 108A, e.g., a conical shape, and is dehydrated.
  • a forming step 640 the fabricated product is subjected to a heat-pressure-drying process by setting the product in a mold having the shape of the diaphragm 108A and preheated at about 160°C to about 220°C, e.g., 200°C.
  • the diaphragm 108A is obtained as a molded product having a predetermined shape.
  • an immersion step 645 the molded product obtained in the forming step 640 is immersed in a pre-formulated immersion solution, so as to impregnate the product with the solution. Thereafter, the product impregnated with the solution is dried against wind at room temperature for about 10 minutes, and is further dried for about 10 minutes in an oven set at an appropriate temperature, e.g., 120°C. Thus, a water-repellent synthetic resin film is formed on the surface of the molded product.
  • the immersion solution is prepared by diluting 50 g of a saturated copolymer polyester resin solution, e.g., a product designated as "Polyester LP-011 S50TO” (manufactured by Nippon Synthetic Chemical Industry, Co., Ltd.) with 200 cc of methyl ethyl ketone, adding 10 cc of a fluorine-type water repellent, e.g., a product designated as "SURFRON SR-137AR” (manufactured by SEIMI Chemical Co., Ltd.) to the resultant mixture, and then stirring the resultant mixture.
  • a saturated copolymer polyester resin solution e.g., a product designated as "Polyester LP-011 S50TO” (manufactured by Nippon Synthetic Chemical Industry, Co., Ltd.)
  • a fluorine-type water repellent e.g., a product designated as "SURFRON SR-137AR” (manufactured by SEIMI Chemical
  • the molded diaphragm is subjected to a trimming process in a trimming step 650 so as to have predetermined inner and outer shapes.
  • the diaphragm 108A having a predetermined shape for example, a conical shape with a diameter of 160 mm is obtained.
  • a meta-type aramid resin is mixed in a pulp material which includes natural pulp as a principal material and is water-proofed with a water-repellent.
  • any other material which is water-proof synthetic pulp having a minute film-like shape may be mixed in the pulp material in the place of a meta-type aramid resin.
  • water-repellents used for the purposes of pulp affixation, immersion, and addition of a synthetic resin in the above description are fluorine type, it is also applicable to use water-repellents of other kinds.
  • any other material can be employed as long as the material sufficiently forms a film after being dried and does not degrade the paper diaphragm in terms of either the characteristics or the sound quality thereof.
  • an acryl-type resin may be employed.
  • the immersion step may be replaced by any other method as long as the molded product (diaphragm) is appropriately impregnated with the synthetic resin so that a water-repellent synthetic resin film with an appropriate thickness is formed.
  • the above-mentioned immersion step 645 may be interpreted as an impregnation step.
  • a diaphragm according to a third example of the present invention is produced as follows. Since the configuration of the loud speaker of the present example is basically the same as those of the loud speakers 120 (Example 1; Figure 4) and 220 (Example 2; Figure 8), the description thereof is omitted. Since the same flow chart described in Example 2 ( Figure 10) applies to the production process of the loud speaker of the present example, the description thereof is also omitted.
  • UKP having a freeness (Canadian Freeness) of 550 cc is beaten so as to give a slurry of UKP.
  • the UKP functions as a principal material.
  • modified polyester fibers (melting point: about 120°C to about 180°C; fiber length: about 1 to about 15 mm; thickness: about 0.5 to about 5 deniers) are first added in an amount of about 1% to about 50% by weight based on the absolute dry weight of the UKP.
  • modified polyester fibers having a melting point of 130°C, a fiber length of 5 mm, and a thickness of 2 deniers are added in an amount of 10% by weight based on the absolute dry weight of the UKP.
  • meta-type aramid resin pulp is added in an amount of 5% to 20% by weight based on the absolute dry weight of the UKP.
  • "CONEX pulp” (manufactured by Teijin Ltd.) is added in an amount of 10% by weight based on the absolute dry weight of the UKP.
  • a fluorine-type water repellent is added in an amount of about 2 to about 20 cc to an absolute dry weight of 100 g of the UKP.
  • 10 cc of "DICGUARD F-400" manufactured by Dainippon Ink and Chemicals, Inc.
  • an aluminium sulfate is employed to adjust the pH of the slurry to be in the range of about 4.5 to about 5.0.
  • the fluorine-type water repellent is affixed to the UKP.
  • a molding step (a paper-fabrication step), a forming step, an immersion step, and a trimming step are conducted in the same manner as in Example 2, the descriptions thereof being omitted.
  • a diaphragm for example, having a conical shape with a diameter of 160 nm, is obtained.
  • low-melting point polyester fibers and a meta-type aramid resin are mixed in a pulp material which includes natural pulp as a principal material and is water-proofed with a water-repellent.
  • any other material which is water-proof synthetic pulp having a minute film-like shape may be mixed in the pulp material in the place of a meta-type aramid resin.
  • shape of the fibers to be mixed there is no limitation to the shape of the fibers to be mixed, either.
  • water-repellents used for the purposes of pulp affixation, immersion, and addition of a synthetic resin in the above description are fluorine type, it is also applicable to use water-repellents of other kinds.
  • any other material can be employed as long as the material sufficiently forms a film after being dried and does not degrade the paper diaphragm in terms of either the characteristics or the sound quality thereof.
  • an acryl-type resin may be employed.
  • the buckling strengths of the diaphragms produced according to Examples 1 and 2 and conventional diaphragms A and B were measured as follows. Each diaphragm was immersed in the above-mentioned car shampoo solution for 24 hours. Thereafter, each conical-shaped diaphragm was placed on a surface plate face down, the diaphragm being in a moistened state. A disk was placed on a neck portion of each diaphragm maintained in this state. Thus, a load was applied onto the disk in such a manner that the disk and the surface plate were kept parallel to each other. The load was gradually increased until reaching a value at which each diaphragm was destroyed, which value was defined as a buckling destruction strength. The same measurement was conducted for diaphragms, both conventional and according to the present invention, that were not immersed in car shampoo (hereinafter referred to as "non-immersed diaphragms").
  • Table 1 shows the measured buckling destruction strength values. Each of the reduction rates shown in Table 1 represents a rate by which the buckling destruction strength of each diaphragm decreased after immersion, with respect to the buckling destruction strength of the non-immersed diaphragm.
  • the diaphragms produced according to Examples 2 and 3 of the present invention have smaller reduction rates of buckling destruction strength than the conventional diaphragms.
  • the diaphragms according to the present invention have excellent water-proofness and maintain high buckling strength.
  • the reduction rate of the diaphragm of Example 3 is smaller than that of the diaphragm of Example 2, indicating the superior water-proofness and high buckling strength of the diaphragm of Example 3.
  • a molded product is obtained by dry-molding a principal material of water-repellentized natural pulp, which is mixed with water-proof synthetic pulp having a minute film-like shape. Furthermore, the molded product is impregnated with a synthetic resin solution mixed with a water-repellent and is dried, so as to obtain a water-repellent synthetic resin film on the surface of the molded product. As a result, water is prevented from entering the diaphragm, so that the water absorption of the diaphragm is reduced without ruining the advantages of the paper diaphragm and without requiring specific jigs and equipment.
  • the diaphragm has a sufficient resistance against surfactants. Moreover, since the water-proof synthetic pulp having a minute film-like shape adheres to the surface of the natural pulp fibers, such as wood pulp, so as to form a film thereon strongly entangled with the natural pulp, the diaphragm maintains a strong buckling strength even ifwaterenters the inside of the diaphragm so as to moisten it. In addition, the diaphragm, although water-repellent and water-proofed, can be produced at a relatively low cost. By using the above-mentioned diaphragm, a high performance loud speaker having an excellent water-proofness can be obtained.
  • Figure 11 is a half cross-sectional view showing a configuration for a loud speaker 420 according to a fourth example of the present invention.
  • Figure 12 is a half cross-sectional view showing a configuration for a voice coil 409 incorporated in the loud speaker 420.
  • the loud speaker 420 differs from the loud speaker 120 with respect to the voice coil 409.
  • a configuration for the voice coil 409 will be described with reference to Figure 12.
  • a bobbin 413 included in the voice coil 409 is formed by using a sheet which includes water-proofed and heat-resistant synthetic pulp having a minute film-like shape as a principal material, the synthetic pulp exhibiting auto-fusion properties by pressure-heating.
  • a sheet which includes water-proofed and heat-resistant synthetic pulp having a minute film-like shape as a principal material, the synthetic pulp exhibiting auto-fusion properties by pressure-heating As the film-like synthetic pulp, pulp composed of a meta-type aromatic polyamide (aramid) may be used.
  • An inorganic filler such as mica
  • An inorganic filler is mixed in the film-like synthetic pulp in an amount of about 20% to about 50%, and preferably about 35% to about 50%, by weight.
  • water-proof and heat-resistant synthetic fibers are mixed in the film-like synthetic pulp in an amount of about 5% to about 30%, and preferably about 15% to about 25%, by weight.
  • synthetic fibers short fibers composed of para-type aromatic polyamide may be used.
  • the film-like synthetic pulp in which the inorganic filler and the synthetic fibers are mixed in the above-mentioned manner, is subjected to a paper-fabrication process and a heat-pressure process by means of a calender so as to form a sheet to be used as the bobbin 413.
  • the thickness of the sheet after the calender process is typically about 30 to about 500 f,.lm.
  • the bulk density is typically about 0.6 to about 1.5 g/cm 3 .
  • a flame-resistant sheet with excellent thermal stability can be obtained by the inclusion of the inorganic filler, such as mica, in an amount of about 35% to about 50% by weight.
  • thermosetting resin such as epoxy resin or phenol resin
  • the impregnated amountofthe thermosetting resin is less than about 15% by weight, the water-proofness and the stiffness of the sheet are deteriorated. If the impregnated amount of the thermosetting resin is more than about 30% by weight, the sheet becomes fragile.
  • the meta-type aromatic polyamide pulp exists in an amount of about 10% to about 80% by weight. If the meta-type aromatic polyamide pulp content is less than about 10% by weight, the sheet does not attain sufficient strength. If the meta-type aromatic polyamide pulp content is more than about 80% by weight, the specific elasticity of the sheet becomes insufficient.
  • para-type aromatic polyamide short fibers exist in an amount of about 5% to about 30% by weight in the sheet.
  • Mica is most preferable as the inorganic filler to be mixed in the sheet. Since the sheet is subjected to a paper-fabrication process, in particular, it is preferable to use mica grains having diameters smaller than about 16 mesh and larger than about 200 mesh as the principal material. If the inorganic filler content is less than about 35% by weight, the heat-resistance and stiffness of the sheet become slightly insufficient. If the inorganic filler content is more than about 50% by weight, the sheet surface has too large bumps and dents, which results in fragility in terms of the physical characteristics of the material.
  • the paper to be used in the paper-fabrication process may be the usual round net type or long net type.
  • the specific elasticity and the water-proofness of the resultant sheet can be further improved.
  • the calender process the auto-fusion properties of the meta-type aromatic polyamide (aramid) pulp are exhibited, and the adhesion of the mica is improved.
  • the water-proofness of the sheet is also improved so that moisture is prevented from being absorbed into the voice coil 409 (bobbin 413), the generation of gas and/or voids due to an increase in the temperature of the voice coil 409 is reduced, thereby further improving the heat-resistance of the voice coil 409.
  • the above-mentioned sheet has excellent water-proofness. Since the sheet has moderate bumps and dents on the surface thereof, it exhibits excellent adhesion. By cutting this sheet into strips and forming the strips into cylinders, the light-weight bobbin 413 having excellent flame resistance, stiffness, and thermal stability can be obtained.
  • a coil portion 415 is formed by winding a heat-resistant magnet wire around the outer periphery of the bobbin 413.
  • Reinforcement paper 414 is wound around the outer periphery of the bobbin 413 excluding the coil portion 415 for reinforcement and insulation.
  • the voice coil 409 shown in Figure 12 is obtained.
  • the above-mentioned advantages of light-weight, flame resistance, stiffness, and thermal stability of the voice coil 409 (bobbin 413) can be further improved.
  • the voice coil 409 thus produced has excellent heat-resistance and stiffness, and yet has a small weight.
  • the voice coil 409 By incorporating the voice coil 409 into a loud speaker, the bobbin 413 is prevented from being burnt and the coil 415 is prevented from falling off the bobbing 413, thereby providing a loud speaker having a stably excellent performance.
  • Tables 2 and 3 shown below indicate typical measurement values of the physical characteristics, e.g., thermal shrinkage, of three sheets to be used for the bobbin according to the present invention and a conventional material for a bobbin composed only of aromatic polyamide fibers.
  • the three sheets to be used for the bobbin according to the present invention are all obtained by using aromatic polyamide fibers, mica powder, and phenol resin in three different content ratios as shown in Tables 2 and 3. These data were measured by a common method and the detailed description of the measurement method itself is omitted here.
  • the sheets according to the present invention have excellent heat resistance and good dimensional stability. Therefore, by using any ofthese sheets for a voice coil incorporated in a loud speaker for receiving a large input, the voice coil can achieve sufficient characteristics.
  • the sheets of the present invention all have tight weight and excellent stiffness, as well as good water-proofness.
  • a metal powder layer on the surface of the outer surface of the bobbin 413 of the voice coil 409 shown in Figures 11 and 12 by vapor-depositing metal powder composed of light-weight nonmagnetic material, e.g., aluminum, on the surface and thereafter coating resin on the surface.
  • a metal powder layer may be formed by coating resin mixed with the above-mentioned metal powder on the surface.
  • the voice coil for a loud speaker is formed by using as a bobbin a sheet which is obtained by subjecting water-proof and heat-resistant synthetic pulp having a minute film-like shape and exhibiting auto-fusion properties by a pressure-heating or a calender process, e.g., aromatic polyamide pulp, mixed with inorganic fillers and water-proof heat-resistant synthetic fibers, to a paper-fabrication process and subjecting the synthetic pulp to a heat-press process by means of a calender.
  • a pressure-heating or a calender process e.g., aromatic polyamide pulp, mixed with inorganic fillers and water-proof heat-resistant synthetic fibers
  • the voice coil has improved water-proofness, so that it will exhibit stably high performance even when applied to uses such as loud speakers for the doors of automobiles, where water-proofness is a strong requirement.
  • the above-described loud speaker according to the present invention incorporates a diaphragm having high internal loss and large stiffness, and therefore is capable of sound reproduction with little distortion in a broad range of frequencies as well as having improved water-proofness.
  • the loud speaker is made capable of withstanding a large input signal applied thereto.
  • a high-performance loud speaker having excellent flame-resistance and water-proofness can be provided.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Manufacturing & Machinery (AREA)
  • Diaphragms For Electromechanical Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
EP95104716A 1994-03-31 1995-03-30 Lautsprecher und Verfahren zu seiner Herstellung Withdrawn EP0675667A3 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP6266994A JPH07274283A (ja) 1994-03-31 1994-03-31 スピーカ用振動板及びその製造方法
JP62669/94 1994-03-31
JP6266994 1994-03-31
JP7582994 1994-04-14
JP75829/94 1994-04-14
JP07582994A JP3561946B2 (ja) 1994-04-14 1994-04-14 スピーカ用振動板及びその製造方法

Publications (2)

Publication Number Publication Date
EP0675667A2 true EP0675667A2 (de) 1995-10-04
EP0675667A3 EP0675667A3 (de) 2003-02-19

Family

ID=26403719

Family Applications (1)

Application Number Title Priority Date Filing Date
EP95104716A Withdrawn EP0675667A3 (de) 1994-03-31 1995-03-30 Lautsprecher und Verfahren zu seiner Herstellung

Country Status (4)

Country Link
US (2) US5875253A (de)
EP (1) EP0675667A3 (de)
CN (2) CN1127283C (de)
TW (1) TW354866B (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1248493A2 (de) * 2001-04-02 2002-10-09 Pioneer Corporation Lautsprechermembran und Verfahren zu deren Herstellung

Families Citing this family (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3569413B2 (ja) * 1997-03-25 2004-09-22 パイオニア株式会社 スピーカ装置及びスピーカ装置の製造方法
US6412594B1 (en) * 1999-10-05 2002-07-02 Shoot The Moon Products Ii, Llc Water gun with sound effects module
DE20005543U1 (de) * 2000-03-24 2000-06-21 Peng Jack Vibrationsmembranlautsprecher
JP2001298791A (ja) * 2000-04-13 2001-10-26 Sony Corp スピーカ及びその製造方法
EP1235462A4 (de) * 2000-10-06 2007-12-05 Mitsubishi Electric Corp Lautsprechervorrichtung sowie verfahren und gerät für dessen herstellung
JP2002135888A (ja) * 2000-10-23 2002-05-10 Pioneer Electronic Corp スピーカ用振動板
US6644182B1 (en) * 2002-09-23 2003-11-11 Chui-Che Chen Method of producing cone diaphragm having color patterns
JP4191555B2 (ja) * 2003-07-29 2008-12-03 シチズン電子株式会社 動電型発音体の製造方法
CN1887027B (zh) * 2003-12-26 2010-08-18 欧积股份有限公司 扬声器防水振动板的制造方法
TWI305997B (en) * 2005-11-25 2009-02-01 Foxconn Tech Co Ltd Sound resistance material and manufacture method
WO2007117045A1 (ja) * 2006-06-21 2007-10-18 Panasonic Corporation スピーカおよびこれを用いたスピーカ装置ならびにこのスピーカを用いた電子機器および車両
JP4779837B2 (ja) * 2006-07-05 2011-09-28 ヤマハ株式会社 スピーカー用振動板及びスピーカー用振動板の製造方法
US8320604B1 (en) * 2007-05-02 2012-11-27 Richard Vandersteen Composite loudspeaker cone
US20110116658A1 (en) * 2007-10-05 2011-05-19 Panasonic Coporation Fine natural fiber and speaker diaphragm coated with fine natural fiber
JP2009194467A (ja) * 2008-02-12 2009-08-27 Victor Co Of Japan Ltd ボイスコイル及びスピーカ
US7913808B2 (en) * 2008-03-27 2011-03-29 Bose Corporation Waterproofing loudspeaker cones
JP5470761B2 (ja) * 2008-07-07 2014-04-16 パナソニック株式会社 スピーカ用振動板およびこれを用いたスピーカならびにこのスピーカを用いた電子機器および装置と、前記スピーカ用振動板の製造方法
CN101931842B (zh) * 2009-06-26 2013-07-03 清华大学 音圈骨架及扬声器
CN101931841A (zh) * 2009-06-26 2010-12-29 清华大学 音圈骨架及扬声器
TWI495358B (zh) * 2009-07-03 2015-08-01 Hon Hai Prec Ind Co Ltd 音圈骨架及揚聲器
CN101998210A (zh) * 2009-08-11 2011-03-30 鸿富锦精密工业（深圳）有限公司 音圈骨架及使用该音圈骨架的扬声器
TWI420917B (zh) * 2009-08-18 2013-12-21 Hon Hai Prec Ind Co Ltd 音圈骨架及使用該音圈骨架的揚聲器
TWM382679U (en) * 2009-10-09 2010-06-11 Fortune Grand Technology Inc Ultra-slim type speaker
US20160014520A1 (en) * 2013-02-28 2016-01-14 Mogami Denki Corporation Speaker diaphragm
KR101586182B1 (ko) * 2013-11-01 2016-01-15 서어모스 케이.케이. 스피커 및 스피커용 하우징
CN106028234B (zh) * 2016-05-31 2021-08-31 歌尔股份有限公司 一种振膜及扬声器单体
DE102017119865A1 (de) * 2016-09-07 2018-03-08 Sennheiser Electronic Gmbh & Co. Kg Elektrodynamischer Schallwandler und Verfahren zum Herstellen eines elektrodynamischen Schallwandlers
CN109348395B (zh) * 2018-11-08 2023-07-04 苏州夸克新材料科技有限公司 一种吸音材料薄片的制备方法
CN110219206B (zh) * 2019-06-24 2021-12-24 国光电器股份有限公司 一种防水阻燃纸盆、扬声器及纸盆的制备方法

Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4112168A (en) * 1977-03-23 1978-09-05 Motorola, Inc. High stiffness speaker cone
US4308094A (en) * 1977-02-02 1981-12-29 Sanyo Electric Co., Ltd. Diaphragm for speaker and method of producing same
US4518642A (en) * 1983-04-15 1985-05-21 International Jensen Incorporated Loudspeaker diaphragm and method for making same
JPS60254999A (ja) * 1984-05-31 1985-12-16 Onkyo Corp 音響変換器用コイルボビン
US4582163A (en) * 1983-05-10 1986-04-15 U.S. Philips Corporation Electro-acoustic transducer with high air permeable diaphragm
JPS6180999A (ja) * 1984-09-27 1986-04-24 Matsushita Electric Ind Co Ltd スピ−カ用ボイスコイル
JPS61227500A (ja) * 1985-04-01 1986-10-09 Pioneer Electronic Corp スピ−カ用ボイスコイルボビン
US4674592A (en) * 1984-11-14 1987-06-23 Alpine Electronics Inc. Diaphragm for use in electro-acoustic transducer
JPS62265891A (ja) * 1986-05-14 1987-11-18 Matsushita Electric Ind Co Ltd スピ−カ用振動板
JPS6460100A (en) * 1987-08-31 1989-03-07 Foster Electric Co Ltd Voice coil bobbin for speaker
JPH01120199A (ja) * 1987-11-02 1989-05-12 Totoku Electric Co Ltd 超耐熱ボイスコイルの製造法
EP0457474A2 (de) * 1990-05-18 1991-11-21 Sony Corporation Verfahren zur Herstellung einer akustichen Membran
US5206466A (en) * 1990-04-13 1993-04-27 Sansui Electric Co., Ltd. Diaphragm for speaker
US5274199A (en) * 1990-05-18 1993-12-28 Sony Corporation Acoustic diaphragm and method for producing same
EP0594435A1 (de) * 1992-10-22 1994-04-27 Asahi Kasei Kogyo Kabushiki Kaisha Lautsprecherkonus und Verfahren zu seiner Herstellung
US5790481A (en) * 1996-11-21 1998-08-04 Meitner; Edmund Retrofitable CD player system
US20080219459A1 (en) * 2004-08-10 2008-09-11 Anthony Bongiovi System and method for processing audio signal
EP1971035A1 (de) * 2007-03-16 2008-09-17 Harman International Industries, Incorporated Audio-Steuerungssystem für ein Fahrzeug

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5419257B2 (de) * 1973-12-14 1979-07-13
US4071111A (en) * 1976-04-28 1978-01-31 Acoustic Fiber Sound Systems, Inc. Weatherproof loudspeaker assembly and method of making same
JPS5740718A (en) * 1980-08-22 1982-03-06 Seiko Epson Corp Vertical magnetic recording head
JPS63226689A (ja) * 1986-10-17 1988-09-21 林　顕 発音用振動板
US5283027A (en) * 1989-07-05 1994-02-01 Kabushiki Kaisha Kenwood Method of molding an acoustic diaphragm part of para aromatic polyamide
US5329072A (en) * 1991-05-23 1994-07-12 Yamaha Corporation Acoustic diaphragm

Patent Citations (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4308094A (en) * 1977-02-02 1981-12-29 Sanyo Electric Co., Ltd. Diaphragm for speaker and method of producing same
US4112168A (en) * 1977-03-23 1978-09-05 Motorola, Inc. High stiffness speaker cone
US4518642A (en) * 1983-04-15 1985-05-21 International Jensen Incorporated Loudspeaker diaphragm and method for making same
US4582163A (en) * 1983-05-10 1986-04-15 U.S. Philips Corporation Electro-acoustic transducer with high air permeable diaphragm
JPS60254999A (ja) * 1984-05-31 1985-12-16 Onkyo Corp 音響変換器用コイルボビン
JPS6180999A (ja) * 1984-09-27 1986-04-24 Matsushita Electric Ind Co Ltd スピ−カ用ボイスコイル
US4674592A (en) * 1984-11-14 1987-06-23 Alpine Electronics Inc. Diaphragm for use in electro-acoustic transducer
JPS61227500A (ja) * 1985-04-01 1986-10-09 Pioneer Electronic Corp スピ−カ用ボイスコイルボビン
JPS62265891A (ja) * 1986-05-14 1987-11-18 Matsushita Electric Ind Co Ltd スピ−カ用振動板
JPS6460100A (en) * 1987-08-31 1989-03-07 Foster Electric Co Ltd Voice coil bobbin for speaker
JPH01120199A (ja) * 1987-11-02 1989-05-12 Totoku Electric Co Ltd 超耐熱ボイスコイルの製造法
US5206466A (en) * 1990-04-13 1993-04-27 Sansui Electric Co., Ltd. Diaphragm for speaker
EP0457474A2 (de) * 1990-05-18 1991-11-21 Sony Corporation Verfahren zur Herstellung einer akustichen Membran
US5274199A (en) * 1990-05-18 1993-12-28 Sony Corporation Acoustic diaphragm and method for producing same
EP0594435A1 (de) * 1992-10-22 1994-04-27 Asahi Kasei Kogyo Kabushiki Kaisha Lautsprecherkonus und Verfahren zu seiner Herstellung
US5790481A (en) * 1996-11-21 1998-08-04 Meitner; Edmund Retrofitable CD player system
US20080219459A1 (en) * 2004-08-10 2008-09-11 Anthony Bongiovi System and method for processing audio signal
EP1971035A1 (de) * 2007-03-16 2008-09-17 Harman International Industries, Incorporated Audio-Steuerungssystem für ein Fahrzeug

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 010, no. 121 (E-401), 7 May 1986 (1986-05-07) & JP 60 254999 A (ONKYO KK), 16 December 1985 (1985-12-16) *
PATENT ABSTRACTS OF JAPAN vol. 010, no. 251 (E-432), 28 August 1986 (1986-08-28) & JP 61 080999 A (MATSUSHITA ELECTRIC IND CO LTD), 24 April 1986 (1986-04-24) *
PATENT ABSTRACTS OF JAPAN vol. 011, no. 070 (E-485), 3 March 1987 (1987-03-03) & JP 61 227500 A (PIONEER ELECTRONIC CORP;OTHERS: 01), 9 October 1986 (1986-10-09) *
PATENT ABSTRACTS OF JAPAN vol. 012, no. 150 (E-606), 10 May 1988 (1988-05-10) & JP 62 265891 A (MATSUSHITA ELECTRIC IND CO LTD), 18 November 1987 (1987-11-18) *
PATENT ABSTRACTS OF JAPAN vol. 013, no. 270 (E-776), 21 June 1989 (1989-06-21) & JP 01 060100 A (FOSTER DENKI KK), 7 March 1989 (1989-03-07) *
PATENT ABSTRACTS OF JAPAN vol. 013, no. 364 (E-805), 14 August 1989 (1989-08-14) & JP 01 120199 A (TOTOKU ELECTRIC CO LTD), 12 May 1989 (1989-05-12) *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1248493A2 (de) * 2001-04-02 2002-10-09 Pioneer Corporation Lautsprechermembran und Verfahren zu deren Herstellung
EP1248493A3 (de) * 2001-04-02 2005-08-17 Pioneer Corporation Lautsprechermembran und Verfahren zu deren Herstellung

Also Published As

Publication number Publication date
CN1516522A (zh) 2004-07-28
US5875253A (en) 1999-02-23
US5903658A (en) 1999-05-11
TW354866B (en) 1999-03-21
CN1116397A (zh) 1996-02-07
EP0675667A3 (de) 2003-02-19
CN1247046C (zh) 2006-03-22
CN1127283C (zh) 2003-11-05

Similar Documents

Publication Publication Date Title
US5875253A (en) Loudspeaker and a method for producing the same
JP3055712B2 (ja) スピーカ用振動板
US4410768A (en) Electro-acoustic transducer
JP6371978B2 (ja) 振動板と、これを用いたラウドスピーカと、ラウドスピーカを用いた電子機器、ならびに移動体装置
US20080199028A1 (en) Speaker diaphragm and speaker including the same
US8172035B2 (en) Waterproofing loudspeaker cones
JP2005223807A (ja) 振動板、その製造方法、および、スピーカ装置
JP2005223806A (ja) 振動板、その製造方法、および、スピーカ装置
JPH1046484A (ja) 薄葉耐熱性多孔紙
US4460060A (en) Vibratory diaphragm for loudspeaker
JP3289513B2 (ja) スピーカ
JPH0847082A (ja) スピーカ用振動板
JP3579950B2 (ja) ボイスコイルボビン
JPH06325923A (ja) スピーカ用ボイスコイル及びそれを用いたスピーカ
JP2767702B2 (ja) ボイスコイルボビン
JP3264079B2 (ja) スピーカ
JPH05328487A (ja) スピーカ用振動板およびその製造方法
US20050185818A1 (en) Voice coil bobbin and speaker
CN110351634B (zh) 音盆以及扬声器
EP0086837A1 (de) Vibrierende platte für lautsprecher
JPH04367197A (ja) スピーカ用振動板
JPH0257096A (ja) 音響装置用振動板
JPH0533248A (ja) 複合板およびその製造方法
JPH04367199A (ja) スピーカ用振動板
JPH07274283A (ja) スピーカ用振動板及びその製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19950407

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

RIC1 Information provided on ipc code assigned before grant

Free format text: 7H 04R 7/02 A, 7H 04R 31/00 B, 7H 04R 9/04 B, 7D 21H 13/24 B, 7D 21J 5/00 B

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): DE FR GB

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: PANASONIC CORPORATION

17Q First examination report despatched

Effective date: 20100331

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20100811